Rhododendron rootstock named &#39;Rhodunter 150&#39;

ABSTRACT

A new and distinct  Rhododendron hybrid  plant used as a rootstock that exhibits a high lime tolerance and vigorous growth.

BOTANICAL CLASSIFICATION

Rhododendron hybrid

VARIETAL DENOMINATION

‘Rhodunter 150’

BACKGROUND OF THE INVENTION

The present invention comprises a new and distinct cultivar ofRhododendron hybrid used as a rootstock known by the varietal name‘Rhodunter 150’. The new variety was discovered in Ahrensburg, Germany.The new variety is the result of a planned breeding program between anunnamed and unpatented Rhododendron fortunei variety (female parent) andRhododendron cv. ‘Cunningham's White’ (unpatented male parent).‘Rhodunter 150’ exhibits leaves and flowers that are more similar to itsfemale parent than to its male parent. Additionally, ‘Rhodunter 150exhibits more vigorous growth when compared to its male parent. Further,the new variety differs from both parents in its improved tolerance tolime. In fact, such improved lime tolerance (no Fe-deficiency symptomson soils up to 6.9 pH) distinguishes the new variety from otherRhododendron varieties known to the breeder and satisfied the purpose ofthe breeding program. ‘Rhodunter 150’ has been trial and field testedand has been found to retain its distinctive characteristics and remaintrue to type through successive propagations.

DESCRIPTION OF THE DRAWING

The accompanying photographic drawing illustrates the new variety, withthe color being as nearly true as is possible with color illustrationsof this type:

FIG. 1 shows a view of the new variety grown to a flowering plant.

DESCRIPTION OF THE PLANT

The following detailed description sets forth the characteristics of thenew cultivar. The data which defines these characteristics werecollected by asexual reproductions performed via cuttings or in vitroculture carried out in Ahrensburg, Germany. The color readings andmeasurements were taken outside under natural daylight on plants grownin containers. Color references are primarily to the R.H.S. Colour Chartof The Royal Horticultural Society of London.

PLANT

-   Time to develop roots: About 90 days at 22-25° C.    -   -   Time to produce a finished flowering plant from a rooted            cutting.—About 4 years in the field.        -   Rooting habit.—Spreading.        -   Height.—50 cm. at 3 years.        -   Diameter.—40 cm. at 3 years.        -   Vigor.—Strong.        -   Branching habit.—Compact.        -   Disease, temperature, and drought resistance.—No            observations made to date.        -   Trunk.—Diameter: 3 cm. at 5 cm. above soil height at 4            years. Bark color: Green to reddish-brown. Texture: Hard.            Pubescence: Absent. Form: Erect.        -   Lateral branches.—Diameter: 5-7 mm. Internode length:            1-2 cm. Texture: Hard. Pubescence: Absent. Color: Green to            reddish-brown.        -   Leaves.—Arrangement: Alternate. Length: 15 cm. maximum.            Width: 5.5 cm. maximum. Shape: Oblanceolate. Apex: Broad.            Base: Tapering. Margin: Entire. Texture: Hard. Pubescence:            Absent. Color: Upper surface: 147B for young leaves and 147A            for mature leaves. Lower surface: 147C for both young and            mature leaves. Margins: Entire. Venation pattern: Dense            venation with a pronounced central vein. Vein color: Upper            surface: 144A. Lower surface: 145C.        -   Stipules.—None present.        -   Bracts.—None present.        -   Pedicels.—None present.        -   Petiole.—Length: 3 cm. Diameter: 4-5 mm. Color: 147C.-   Flower:    -   -   Natural flowering season.—Beginning of May until the end of            May in Northern Germany.        -   Form.—Round spike.        -   Lastingness of bloom.—From one to two weeks.        -   Average number of blooms on a plant.—Approximately 20 on a            plant with a diameter of 40 cm.        -   Fragrance.—Typical of Rhododendron fortunei.        -   Buds (described before bursting).—Shape: Oblong. Width:            20 mm. Length: 40 mm. Color: 34C.        -   Spike.—Number of flowers per spike: 10-15. Length: 15 cm.            Diameter: 15 cm.        -   Corolla petals.—Form: Zygomorphic. Shape: Widely            funnel-shaped. Number: 7. Length: Approximately 55 mm.            Width: Approximately 50 mm. Margin: Undulate. Texture:            Wax-like. Color (both surfaces): 11B when opening and fully            opened.        -   Corolla throat.—Tube length: Approximately 20 mm. Color: 1C.            Texture: Wax-like.        -   Sepals.—Fused.-   Reproductive organs:    -   -   Stamens.—Number: 14.        -   Filament length.—Approximately 30 mm.        -   Anthers.—Shape: Normal Rhododendron type. Color: Yellow.            Length: 5 mm.        -   Pollen.—Amount of pollen: Average. Color of pollen: Light            brown.        -   Pistil.—Number: 1. Length: Approximately 35 mm. Style:            Color: Yellow. Length: Approximately 30 mm.; filiform.            Stigma: Shape: Undivided. Color: Brown.-   Seeds:    -   -   Production.—Seed capsules mature in November when pollinated            in May.        -   Length.—2 mm.        -   Color.—Brown.        -   Number.—Approximately 200 per capsule.

I claim:
 1. A new and distinct variety of Rhododendron hybrid plant, asis herein illustrated and described.